What is REM Sleep?
REM sleep stands for Rapid Eye Movement sleep. It is a normal stage of sleep where the eyes move rapidly in a random pattern. It is classified into two categories, tonic and phasic. Phasic being the time where they eye moves in rapid bursts and tonic being the time inbetween these sudden burts of movement. REM Sleep usually accounts for about 20-25% (about 90-120 minutes) of total sleep. During a normal night of sleep 4-5 periods of REM Sleep occur. They usually start out short and grow longer as the night wears on. REM sleep is associated with dreaming as most dreams occur during this time.

How is REM Sleep different than NREM Sleep?
REM sleep physiologically differs from non Rapid Eye Movement Sleep (NREM) in that the person undergoes complete muscle shutdown except for their eyes which are moving constantly. It is like they can still look around but are paralyzed.

How does REM Sleep relate to optics?
Some theories speculate that the random eye movements associated with REM are actually the eyes trying to focus on what they see while the person is in a dream. But other theories say this theory can not be true as fetuses and blind people exhibit the same behaviour. Another theory is that REM Sleep is used to lubricate the cornea, warm the brain and stimulate/stabilize neuro transmitters that were not used during the day.

Applications of REM Sleep
We are still not entirely sure what REM sleep's purpose is but many people are working to solve this riddle. What scientists have learned about REM Sleep includes:
- People will die if they do not have it
-Without enough REM the body will physiologically change for the worse
-Children who do not get enough REM or if it is continually interrupted develop sleep and psycological problems later on in life
-Some speculate that during REM Sleep are brains sort through our memories and pick the relevant ones to keep and store

Brain Wave Activity
E.O.G.- test where retina movement is measured
E.M.G.- Detects abnormal muslce electrical activity

Alpha- when the brain is aroused and in active mental activites
Beta- when the brain is non-aroused and not in active mental activites
Theta- when the brain is non-aroused to the point of forgetfulness or day dreaming
Delta- deep dreamless sleep
References:
http://en.wikipedia.org/wiki/Rapid_eye_movement_sleep#cite_note-0
http://www.uptodate.com/contents/stages-and-architecture-of-normal-sleep
http://www.youtube.com/watch?v=fStZPQuGWbs
http://www.web-us.com/brainwavesfunction.htm
http://www.medicinenet.com/electromyogram/article.htm
en.wikipedia.org/wiki/EOG

By:Duane